1. Field of the Invention
The present invention relates to a system for assessing movement and agility skills and, in particular, to a wireless position tracker for continuously tracking and determining player position during movement in a defined physical space through player interaction with tasks displayed in a computer generated, specially translated virtual space for the quantification of the player""s movement and agility skills based on time and distance traveled in the defined physical space.
2. The Related Art
Sports specific skills can be classified into two general conditions:
1) Skills involving control of the body independent from other players; and
2) Skills including reactions to other players in the sports activity. The former includes posture and balance control, agility, power and coordination. These skills are most obvious in sports such as volleyball, baseball, gymnastics, and track and field that demand high performance from an individual participant who is free to move without opposition from a defensive player. The latter encompasses interaction with another player-participant. This includes various offense-defense situations, such as those that occur in football, basketball, soccer, etc.
Valid testing and training of sport-specific skills requires that the player be challenged by unplanned cues which prompt player movement over distances and directions representative of actual game play. The player""s optimum movement path should be selected based on visual assessment of his or her spatial relationship with opposing players and/or game objective. A realistic simulation must include a sports relevant environment. Test methods prompting the player to move to fixed ground locations are considered artificial. Nor are test methods employing static or singular movement cues such as a light or a sound consistent with accurate simulations of actual competition in many sports.
To date, no accurate, real time model of the complex, constantly changing, interactive relationship between offensive and defensive opponents engaging in actual competition exists. Accurate and valid quantification of sport-specific movement capabilities necessitates a simulation having fidelity with real world events.
At the most primary level, sports such as basketball, football and soccer can be characterized by the moment to moment interaction between competitors in their respective offensive and defensive roles. It is the mission of the player assuming the defensive role to xe2x80x9ccontainxe2x80x9d, xe2x80x9cguardxe2x80x9d, or neutralize the offensive opponent by establishing and maintaining a real-time synchronous relationship with the opponent. For example, in basketball, the defensive player attempts to continually impede the offensive player""s attempts to drive to the basket by blocking with his or her body the offensive player""s chosen path, while in soccer the player controlling the ball must maneuver the ball around opposing players.
The offensive player""s mission is to create a brief asynchronous event, perhaps of only a few hundred milliseconds in duration, so that the defensive player""s movement is no longer in xe2x80x9cphasexe2x80x9d with the offensive player""s. During this asynchronous event, the defensive player""s movement no longer mirrors, i.e., is no longer synchronous with, his or her offensive opponent. At that moment, the defensive player is literally xe2x80x9cout of positionxe2x80x9d and therefore is in a precarious position, thereby enhancing the offensive player""s chances of scoring. The offensive player can create an asynchronous event in a number of ways. The offensive player can xe2x80x9cfake outxe2x80x9d or deceive his or her opponent by delivering purposefully misleading information as to his or her immediate intentions. Or the offensive player can xe2x80x9coverwhelmxe2x80x9d his opponent by abruptly accelerating the pace of the action to levels exceeding the defensive player""s movement capabilities.
To remain in close proximity to an offensive opponent, the defensive player must continually anticipate or xe2x80x9creadxe2x80x9d the offensive player""s intentions. An adept defensive player will anticipate the offensive player""s strategy or reduce the offensive player""s options to those that can easily be contained. This must occur despite the offensive player""s attempts to disguise his or her actual intentions with purposely deceptive and unpredictable behavior. In addition to being able to xe2x80x9creadxe2x80x9d, i.e., quickly perceive and interpret the intentions of the offensive player, the defensive player must also possess adequate sport-specific movement skills to establish and maintain the desired (from the perspective of the defensive player) synchronous spatial relationship.
These player-to-player interactions are characterized by a continual barrage of useful and purposefully misleading visual cues offered by the offensive player and constant reaction and maneuvering by the defensive participant. Not only does the defensive player need to successfully interpret visual cues xe2x80x9cofferedxe2x80x9d by the offensive player, but the offensive player must also adeptly interpret visual cues as they relate to the defensive player""s commitment, balance and strategy. Each player draws from a repertoire of movement skills which includes balance and postural control, the ability to anticipate defensive responses, the ability to generate powerful, rapid, coordinated movements, and reaction times that exceed that of the opponent. These sport-specific movement skills are often described as the functional or motor related components of physical fitness.
The interaction between competitors frequently appears almost chaotic, and certainly staccato, as a result of the xe2x80x9cduelingxe2x80x9d for advantage. The continual abrupt, unplanned changes in direction necessitate that the defensive player maintain control over his or her center of gravity throughout all phases of movement to avoid over committing. Consequently, movements of only fractions of a single step are common for both the defensive and offensive players. Such abbreviated movements insure that peak or high average velocities are seldom, if ever, achieved. Accordingly, peak acceleration and power are more sensitive measures of performance in the aforementioned scenario. Peak acceleration of the center of mass can be achieved more rapidly than peak velocity, often in one step or less, while power can relate the acceleration over a time interval, making comparisons between players more meaningful.
At a secondary level, all sports situations include decision-making skills and the ability to focus on the task at hand. The present invention simulation trains participants in these critical skills. Therefore, athletes learn to be xe2x80x9csmarterxe2x80x9d players due to increased attentional skills, intuition, and critical, sports related reasoning.
Only through actual game play, or truly accurate simulation of game play, can the ability to correctly interpret and respond to sport specific visual cues be honed. The same requirement applies to the refinement of the sport-specific components of physical fitness that is essential for adept defensive and offensive play. These sport-specific components include reaction time, balance, stability, agility and first step quickness.
Through task-specific practice, athletes learn to successfully respond to situational uncertainties. Such uncertainties can be as fundamental as the timing of the starter""s pistol, or as complex as detecting and interpreting continually changing, xe2x80x9canalogxe2x80x9d stimuli presented by an opponent. To be task-specific, the type of cues delivered to the player must simulate those experienced in the player""s sport. Task-specific cuing can be characterized, for the purposes of this document, as either dynamic or static.
Dynamic cuing delivers continual, xe2x80x9canalogxe2x80x9d feedback to the player by being responsive to, and interactive with, the player. Dynamic cuing is relevant to sports where the player must possess the ability to xe2x80x9creadxe2x80x9d and interpret xe2x80x9ctelegraphingxe2x80x9d kinematic detail in his or her opponent""s activities. Players must also respond to environmental cues such as predicting the path of a ball or projectile for the purposes of intercepting or avoiding it. In contrast, static cuing is typically a single discreet event, and is sport relevant in sports such a track and field or swimming events. Static cues require little cerebral processing and do not contribute to an accurate model of sports where there is continuous flow of stimuli necessitating sequential, real time responses by the player. At this level, the relevant functional skill is reaction time, which can be readily enhanced by the present invention""s simulation.
In sports science and coaching, numerous tests of movement capabilities and reaction time are employed. However, these do not subject the player to the type and frequency of sport-specific dynamic cues requisite to creating an accurate analog of actual sports competition described above.
For example, measures of straight-ahead speed such as the 100-meter and 40 yard dash only subject the player to one static cue, i.e, the sound of the gun at the starting line. Although the test does measure a combination of reaction time and speed, it is applicable to only one specific situation (running on a track) and, as such, is more of a measurement of capacity, not skill. In contrast, the player in many other sports, whether in a defensive or offensive role, is continually bombarded with cues that provide both useful and purposely misleading information as to the opponent""s immediate intentions. These dynamic cues necessitate constant, real time changes in the player""s movement path and velocity; such continual real-time adjustments preclude a player from reaching maximum high speeds as in a 100-meter dash. Responding successfully to dynamic cues places constant demand on a player""s agility and the ability to assess or read the opposing player intentions.
There is another factor in creating an accurate analog of sports competition. Frequently, a decisive or pivotal event such as the creation of an asynchronous event does not occur from a preceding static or stationary position by the players. For example, a decisive event most frequently occurs while the offensive player is already moving and creates a phase shift by accelerating the pace or an abrupt change in direction. Consequently, it is believed that the most sensitive indicators of athletic prowess occur during abrupt changes in vector direction or pace of movement from xe2x80x9cpreexisting movementxe2x80x9d. All known test methods are believed to be incapable of making meaningful measurements during these periods.
Known in the art are various types of virtual reality or quasi virtual reality systems used for entertainment purposes or for measuring physical exertion. Examples of such systems are U.S. Pat. No. 5,616,078, to Oh, entitled xe2x80x9cMotion-Controlled Video Entertainment Systemxe2x80x9d; U.S. Pat. No. 5,423,554, to Davis, entitled xe2x80x9cVirtual Reality Game Method and Apparatusxe2x80x9d; U.S. Pat. No. 5,638,300, to Johnson, entitled xe2x80x9cGolf Swing Analysis Systemxe2x80x9d; U.S. Pat. No. 5,524,637, to Erickson, entitled xe2x80x9cInteractive System for Measuring Physiological Exertionxe2x80x9d; U.S. Pat. No. 5,469,740, to French et al., entitled xe2x80x9cInteractive Video Testing and Training Systemxe2x80x9d; U.S. Pat. No. 4,751,642, to Silva et al., entitled xe2x80x9cInteractive Sports Simulation System with Physiological Sensing and Psychological Conditioningxe2x80x9d; U.S. Pat. No. 5,239,463, to Blair et al., entitled xe2x80x9cMethod and Apparatus for Player Interaction with Animated Characters and Objectsxe2x80x9d; and U.S. Pat. No. 5,229,756, to Kosugi et al., entitled xe2x80x9cImage Control Apparatusxe2x80x9d. These prior art systems lack realism in their presentations and/or provide no measurement or inadequate measurement of physical activity.
The present invention provides a system for quantifying physical motion of a player or subject and providing feedback to facilitate training and athletic performance. A preferred system creates an accurate simulation of sport to quantify and train several novel performance constructs by employing:
sensing electronics (preferably optical sensing electronics as discussed below) for determining, in essentially real time, the player""s three dimensional positional changes in three or more degrees of freedom (three dimensions); and
computer controlled sport specific cuing that evokes or prompts sport specific responses from the player.
In certain protocols of the present invention, the sport specific cuing could be characterized as a xe2x80x9cvirtual opponentxe2x80x9d, that is preferablyxe2x80x94but not necessarilyxe2x80x94kinematically and anthropomorphically correct in form and action. Though the virtual opponent could assume many forms, the virtual opponent is responsive to, and interactive with, the player in real time without any perceived visual lag. The virtual opponent continually delivers and/or responds to stimuli to create realistic movement challenges for the player. The movement challenges are typically comprised of relatively short, discrete movement legs, sometimes amounting to only a few inches of displacement of the player""s center of mass. Such movement legs are without fixed start and end positions, necessitating continual tracking of the player""s position for meaningful assessment.
The virtual opponent can assume the role of either an offensive or defensive player. In the defensive role, the virtual opponent maintains a synchronous relationship with the player relative to the player""s movement in the physical world. Controlled by the computer to match the capabilities of each individual player, the virtual opponent xe2x80x9crewardsxe2x80x9d instances of improved player performance by allowing the player to outmaneuver (xe2x80x9cget byxe2x80x9d) him. In the offensive role, the virtual opponent creates asynchronous events to which the player must respond in time frames set by the computer depending on the performance level of the player. In this case, the virtual opponent xe2x80x9cpunishesxe2x80x9d lapses in the player""s performance, i.e, the inability of the player to precisely follow a prescribed movement path both in terms of pace and precision, by outmaneuvering the player.
It is important to note that dynamic cues allow for moment to moment (instantaneous) prompting of the player""s vector direction, transit rate and overall positional changes. In contrast to static cues, dynamic cues enable precise modulation of movement challenges resulting from stimuli constantly varying in real time.
Regardless of the virtual opponent""s assumed role (offensive or defensive), when the protocol employs the virtual opponent, the virtual opponent""s movement cues are xe2x80x9cdynamicxe2x80x9d so as to elicit sports specific player responses. This includes continual abrupt explosive changes of direction and maximal accelerations and decelerations over varying vector directions and distances.
Further summarizing broad aspects of the invention, a testing and training system comprises a continuous tracking system for determining changes in an overall physical location of the player, in a defined physical space; and a computer operatively coupled to the tracking system, for updating in real time a player virtual location in a virtual space corresponding to the physical location of the player in the physical space, for updating a view of the virtual space, and for providing at least one indicia of performance of the player moving in the physical space, wherein the at least one indicia is or is derived from a measure of a movement parameter of the player. According to a particular embodiment of the invention, the at least one indicia of performance that is or is derived from a measure of a movement parameter of the player includes an indicia selected from the group consisting of a measure of work performed by the player, a measure of the player""s velocity, a measure of the player""s power, a measure of the player""s ability to maximize spatial differences over time between the player and a virtual protagonist, a time in compliance, a measure of the player""s acceleration, a measure of the player""s ability to rapidly change direction of movement, a measure of dynamic reaction time, a measure of elapsed time from presentation of a cue to the player""s initial movement in response to the cue, a measure of direction of the initial movement relative to a desired response direction, a measure of cutting ability, a measure of phase lag time, a measure of first step quickness, a measure of jumping or bounding, a measure of cardio-respiratory status, and a measure of sports posture.
According to another aspect of the invention, a method for testing and training includes the steps of tracking an overall physical location of a player within a defined physical space; updating in real time a player virtual location corresponding to the physical location of the player; updating in real time a view of the virtual space; and providing at least one indicia of performance of the player moving in the physical space, the at least one indicia being or being derived from a measure of a movement parameter of the player.
According to yet another aspect of the invention, a game system for two or more players includes a continuous three-dimensional tracking system for each of the players for determining changes in an overall physical location of the respective player in a respective defined physical space; and a computer operatively coupled to the tracking systems for updating in real time player virtual locations in a virtual space corresponding to the physical locations of the players.
According to a further aspect of the invention, a testing and training system for assessing the ability of a player to complete a task, includes tracking means for determining the position of the player within a defined physical space within which the player moves to undertake the task, based on at least two Cartesian coordinates; display means operatively coupled to the tracking means for displaying in a virtual space a player icon representing the instantaneous position of the player therein in scaled translation to the position of the player in the defined physical space; means operatively coupled to the display means for depicting in the virtual space a protagonist; means for defining an interactive task between the position of the player and the position of the protagonist icon in the virtual space; and means for assessing the ability of the player in completing the task based on quantities of distance and time, wherein the task comprises a plurality of segments requiring sufficient movement of the player in the defined physical space to provide quantification of bilateral vector performance of the player in completing the task.
According to a still further aspect of the invention, a testing and training system includes tracking means for tracking a user""s position within a physical space in three dimensions; display means operatively linked to the tracking means for indicating the user""s position within the physical space in essentially real time; means for defining an interactive protocol for the user; means for measuring in essentially real time vertical displacements of the user""s center of gravity as the user responds to interactive protocols; means for calculating the user""s movement velocities and/or accelerations during performance of the protocols; and means for assessing the user""s performance in executing the physical activity.
According to another aspect of the invention, a testing and training system includes tracking means for tracking a user""s movement in three-degrees-of-freedom during his performance of protocols which include unplanned movements over various vector distances; display means operatively linked to the tracking means for indicating the user""s position within the physical space in essentially real time; means for defining a physical activity for the user operatively connected to the display means; and means calculating in essentially real-time the user""s movement accelerations and decelerations; means categorizing each movement leg to a particular vector; and means for displaying feedback of bilateral performance.
According to yet another aspect of the invention, a testing and training system includes tracking means for tracking a user""s position within a physical space in three dimensions; means for displaying a view of a virtual space proportional in dimensions to the physical space; means for displaying, in essentially real time, a user icon in the virtual space at a location which is a spatially correct representation of the user""s position within the physical space; means for defining a physical activity for the user operatively connected to the display means; and means for assessing the user""s performance in executing the physical activity.
According to a further aspect of the invention, a testing and training system includes a tracking system for providing a set of three dimensional coordinates of a user within a physical space; a computer operatively linked to the tracking system to receive the coordinates from the tracking system and indicate the user""s position within the physical space on a display in essentially real time; and wherein the computer includes a program to define a physical activity for the user and measure the user""s performance in executing the activity, to calculate the user""s movement velocities and/or accelerations during performance of the protocols, and to determine a user""s dynamic posture.
According to a still further aspect of the invention, a testing and training system includes a tracking system for providing a set of three dimensional coordinates of a user within a physical space during performance of protocols including unplanned movements over various vector distances; a computer operatively linked to the tracking system to receive the coordinates from the tracking system and indicate the user""s position within the physical space on a display in essentially real time, and to calculate in essentially real-time the user""s movement accelerations and decelerations in executing the activity; and means for displaying feedback of bilateral performance.
According to another aspect of the invention, a reactive power training system includes a reactive training device which provides cues to elicit responsive movements of a subject moves in at least two dimensions, and a resistive training device. The reactive power training device and the strength training device are used in a training sequence.
According to yet another aspect of the invention, a method of reactive power training includes performing a training sequence which includes reactive training bouts on a reactive training device alternated with training on one or more resistive training devices.
To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.